SP8719 Counter

SP8719 520 MHz divide by 80/81 Counter

Features

Quick Reference Data

Supply Voltage 5.0V ± 0.25V

Supply Current 10.5mA typical

Storage temperature range: -55°C to +150°C

Description

The SP8719 is a divide by 80/81, programmable dividers with a maximum specified operating frequency of 520MHz over the temperature range -40 °C to + 85 °C.The signal (clock) inputs are biased internally and require to be capacitor coupled. The output stage is of an unusual low power design featuring dynamic pull-up and optimised for driving CMOS. The 0 to 1 output edge should be used to give the best loop delay performance.

Operating

The inputs are biased internally and coupled to a signal source with suitable capacitors.

If no signal is present the devices will self-oscillate. If this is undesirable, it may be prevented by connecting a 15k resistor from one input to pin 4 (ground). This will reduce the sensitivity.

The circuits will operate down to DC, but slew rate must be better than 100V/µs.

The output stage is of an unusual design and is intended to interface with CMOS. External pull-up resistors or circuits must not be used.